Radome

ABSTRACT

The invention relates to a radome comprising: a substantially sheet-type front plate, the front face of which is transparent and the rear face of which is provided with an opaque layer, at least one cut-out being provided in the opaque layer to act as a light exit; at least one substantially sheet-type light guide situated on the rear face on the opaque layer; and at least one light-emitting element, which is coupled to the light guide so that light enters said light guide, propagates through the at least one light guide, and enters the transparent front plate at the at least one light exit, so that the light is emitted from the front face of the front plate.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a National Stage of International Application No.PCT/EP2016/072643, filed Sep. 23, 2016, which is based upon and claimsthe benefit of priority from prior German Patent Application No. 10 2015220 343.3, filed Oct. 19, 2015, the entire contents of all of which areincorporated herein by reference in their entirety.

TECHNICAL FIELD

The invention relates to a radome, in particular for a radar sensor fora motor vehicle.

PRIOR ART

Radomes are covering elements or covering plates that cover a radartransmitter or radar sensor which emits radar waves. These radomes areused in motor vehicles to protect such radar transmitters, for exampleof radar distance warning systems arranged in the vehicle front, fromthe influence of weather and from damage, such as falling rocks orprecipitation, wherein the radome must at the same time also satisfyvisual requirements of the vehicle manufacturer, because it isintegrated in the vehicle front and helps define the appearance of thevehicle. Radomes of this type have become known for example from DE 19819 709 A1.

It is furthermore one of the functions in a radome that it is at leastsubstantially transparent for electromagnetic radiation in the longwavewavelength range, wherein it is advantageous that it is at leastregionally opaque in the optically visible wavelength range. Thistransparency is achieved by way of coatings or lacquers, such thatmaterials which are transparent in the optically visible wavelengthrange are opaquely covered and thus become non-transparent. As a result,visible three-dimensional structures can be produced, which can also beused as brand symbols, for example.

Inserted to this end is a radome having a front plate which has a frontsurface on its front side and a rear-side surface on its rear side. Thefront side can here be formed by a transparent material which can becoated and covered from the rear side so that optically visiblestructures can be produced.

Such visible structures, however, are not always easily detectable inparticular in the dark or in poor visibility.

Representation of the Invention, Object, Solution, Advantages

It is the object of the invention to provide a radome which is easy tomanufacture and yet exhibits a defined optical effect, in particularalso in the dark and in poor visibility.

The object is achieved by way of the features of claim 1.

An exemplary embodiment of the invention relates to a radome having asubstantially extensive front plate, which is configured to betransmissive on the front side and which is provided on the rear sidewith a layer that does not transmit light, wherein at least one cutoutin the form of a light passage is formed in the layer that does nottransmit light, having at least one substantially extensive light guidewhich is arranged on the rear side at the layer that does not transmitlight, and having at least one light-emitting element which is coupledto the light guide such that light enters the light guide and such thatthe light propagates through the at least one light guide and enters thetransmissive front plate at the at least one light passage such that itexits the front plate on the front side. As a result, a defined lightpassage of the light on the front side can be achieved, with the resultthat a defined illumination is observable if observed from the front. Ifthe cutouts are arranged in a geometric pattern, said pattern is easilydetectable upon illumination from the rear in particular at night ifobserved from the front.

According to the invention, it is advantageous if at least one diffuserelement is arranged at the at least one light guide, which diffuserelement is arranged such that the light propagating through the at leastone light guide enters the diffuser element, propagates through thediffuser element, and exits the diffuser element and enters thetransmissive front plate at the at least ore light passage such that itexits the front plate on the front side.

In an exemplary embodiment of the invention, it is advantageous if anextensive light guide or a plurality of extensive light guides is or areprovided, wherein assigned to each light guide is at least onelight-emitting element, preferably more than one light-emitting element,which is coupled to the light guide for feeding light into the lightguide. As a result, it is possible by way of the light guide to guidelight in a targeted fashion from the light-emitting element into theregion of the cutout, such that the optical effect is easily detectable.It is particularly advantageous here if the cutout has a for examplelinear extent, such that light is detectable along the linear cutout onthe front side of the radome.

It is also advantageous if at least one diffuser element is assigned toat least one of the light guides or each of the light guides. As aresult, the light is guided more intensely in the region of the cutoutinto the front plate because the light is scattered in a targetedfashion in the diffuser, in particular also in the direction of thecutout.

It is particularly advantageous here if the diffuser element is arrangedat an outer periphery of the light guide and in particular rests againstit. The light can then enter the diffuser through the substantiallyextensive light guide at its outer periphery and from there be scatteredin the direction of the transparent front plate. As a result, uniformlighting of the cutout or illumination through the cutout can beeffected.

It is also advantageous if the diffuser element engages around theperimetric outer periphery of the light guide. As a result, perimetriclargely uniform lighting or illumination can be produced. It is possiblein this way to effectively represent extensive figurative motifs.

It is also expedient if the light guide is made of a transparentplastics material and the diffuser element is made of a translucentplastics material. As a result, the light is efficiently transferredfrom the light-emitting means to the diffuser element and is scatteredthere such that it can be guided uniformly into the cutout.

For example, it is advantageous in an exemplary embodiment if the lightguide and the diffuser element are placed to be next to one another inthe form of separately configured parts, it is hereby possible to easilyproduce the two parts separately and to arrange them next to one anotheror inside one another.

It is also expedient if the light guide and the diffuser element arearranged as interconnected parts in neighboring fashion, for example areinterconnected in particular by way of injection molding or adhesivebonding. It is thus possible in a two-component method to easily andwithout complication produce the entire part consisting at least of thelight guide and diffuser element, which also simplifies installation.

It is furthermore expedient if a rear-side cover is provided whichcovers the light guides and any diffuser elements arranged on the rearside of the front plate. Consequently, the radome is also protected frombehind, where the electrical connections are advantageously arranged.

Further advantageous configurations are described by the followingdescription of the figures and by the dependent claims.

BRIEF DESCRIPTION. OF THE DRAWINGS

The invention be explained in more detail below on the basis of at leastone exemplary embodiment with reference to the drawings, in which:

FIG. 1 shows a schematic view of a radome from the front side,

FIG. 2 shows a schematic view of a radome from the rear side,

FIG. 3 shows two light guides having diffuser elements that surroundthem in each case,

FIG. 4 shows a light guide,

FIG. 5 shows a diffuser element, and

FIG. 6 shows a view of the radome in a partial section.

PREFERRED EMBODIMENT OF THE INVENTION

FIG. 1 shows a radome 1 from a front side 2. The radome 1 here has asubstantially extensive front plate 2, whose front side is configured tobe transmissive and whose rear side is provided with a layer 3 that doesnot transmit light, see also FIG. 6. At least one cutout 4 in the formof a light passage is formed here in the layer 3 that does not transmitlight. The cutout 4 that is in the form of a light passage 10 isconfigured in FIG. 1 in the manner of a triangle made from threestraight bars 5 of the cutout 4, which has an annular border 6. At leastone substantially extensive light guide 7 is arranged on the rear sideof the front plate 2 of the radome 1.

FIG. 2 shows that in this exemplary embodiment, three extensive lightguides 7 are arranged, which are arranged on the rear side at the layer3 that does not transmit light. In other exemplary embodiments, otherconfigurations with a different number of light guides can be provided.

Preferably provided per light guide is furthermore at least onelight-emitting element 8, which is coupled to an input coupling element9 of the light guide 7 to couple light into substantially extensivelight guide 7. The respective light-emitting element 8 is coupled to therespective light guide 7 such that light enters the light guide 7 at theinput coupling element 9 and that the light propagates through the atleast one light guide 7 and enters the transmissive front plate 2 at theat least one light passage 10 such that it exits the front plate 2 onthe front side and the illumination effect becomes visible.

It can be seen here that at least one diffuser element 11 is arrangedoptionally at the at least one light guide 7, which diffuser element 11is arranged such that the light propagating through the at least onelight guide 7 enters the diffuser element 11, propagates through thediffuser element and exits the diffuser element 11 again and enters thetransmissive front plate 2 at the at least one light passage 10 suchthat it exits the front plate 2 on the front side and the illuminationeffect becomes visible.

FIG. 3 shows two extensive light guides 7, which are configured likesegments of a circle, which can in particular be configured to be flator curved. Such extensive light guides can be provided individually, ora plurality of such extensive light guides can be provided. In theexample of FIGS. 1 and 2, three such light guides 7 are provided. Atleast one light-emitting element 8 is assigned here to each of the lightguides 7, wherein with preference also more than one light-emittingelement, such as two light-emitting elements, can be assigned, which canbe placed on the input coupling elements 9 such that the light-emittingelements are coupled to the light guide 7 for feeding light into thelight guide 7. The input coupling elements 9 are here of quite differentconfiguration, as is shown in FIG. 3. They are preferably arranged perlight guide 7 at a distance from one another.

In accordance with an exemplary embodiment, at least one diffuserelement 11 is assigned to at least one of the light guides 7 oradvantageously to each of the light guides 7.

FIG. 4 shows an exemplary light guide 7, which is configuredapproximately in the manner of a segment of a circle and has inputcoupling elements 9 which are arranged at the converging end regions 20at a distance from one another. A diffuser element 11 having anapproximately arcuate part 21 and an approximately straight part 22 isassigned to said extensive light guide wherein the diffuser element 11is arranged at an outer periphery 23 of the light guide 7 and inparticular rests against it. This is also shown in FIG. 3. Theapproximately arcuate part 21 here can be, for example, a piece of acircle or be curved in a manner that deviates therefrom. Theapproximately straight part 22 can be straight or have an angle, such asin particular have an angle at the center and form a flat V, forexample.

It is particularly advantageous here if the diffuser element 11 engagesaround the perimetric outer periphery 23 of the light guide 7.Alternatively, the diffuser element 11 can also merely rest against aside or only partially against the outer periphery 23 of the lightguide. It is also possible for a plurality of diffuser elements 11 to beassigned to the light guide 7, which regionally rest against or abut thelight guide.

FIG. 6 shows a section through the radome 1, wherein only a radiallyoutwardly located partial region thereof can be seen. The radome 1 has afront plate 2 made of a transparent material. This material can here inparticular be a plastics material. The front plate 2 can alsofurthermore be coated on its front side 30 with at least one coating 31as to have a scratch-resistant configuration. The extensive front plate2 is transmissive, example transparent.

Provided on the rear side of the front plate 2 is a layer 3 that doesnot transmit light and is at least partly or regionally sprayed onand/or lacquered or injection-molded on or adhesively bonded thereto.For example, regions can be provided with a sprayed-on plastics layer40, wherein the transparent material of the front plate can also beinjection-molded onto the layer that does not transmit light. Radiallyoutwardly, a lacquered surface 41 which is configured such that it doesnot transmit light can be seen. At least one cutout 4 in the form of alight passage 10 is also formed in the layer 3 that does not transmitlight, such as between the regions of the plastics layer 40 and of thelacquered surface 41 in FIG. 6. Arranged on the rear side of the frontplate 2 of the radome 1 is, on the rear side of the layer 3 that doesnot transmit light, a substantially extensive light guide 7. Arrangednext to the light guide 7 and also in the region of the light passage 10is optionally a diffuser element 11. The light is emitted by alight-emitting element 8, input into an input coupling element 9 andinput into the light guide 7. From here, the light is fed into thediffuser element 11 and from here through the light passage 10 into thetransparent front plate 2. Here, the light exits on front side and canthus represent a defined light structure. On the rear side, a cover 50can be provided, which covers the front plate 2 with the light guide 7and optional diffuser element 11.

The light guide 7 is preferably made of a transparent plastics materialand the optional diffuser element is Preferably made of a translucentplastics material.

With respect to the manufacturing of the light guide and of the diffuserelement 11, they can be produced as separately configured parts and beplaced in neighboring fashion at the rear side of the front plate 2.Alternatively, the light guide and the diffuser element can be formed asinterconnected parts next to one another, which are produced together inparticular by injection molding or are adhesively bonded together.

A termination element 60 can be provided on the peripheral side of thefront plate, which termination element 60 is configured for example as acovering ring to cover an emission of light of the radially outercontour of the radome.

LIST OF REFERENCE SYMBOLS

-   1 radome-   2 transmissive, substantially extensive front side or front plate-   3 layer that does not transmit light-   4 cutout-   5 straight bars-   6 annular border-   7 substantially extensive light guide-   8 light-emitting element-   9 input coupling element-   10 light passage-   11 diffuser element-   20 converging end regions-   21 arcuate part-   22 straight part-   23 outer periphery-   30 front side-   31 coating-   40 plastics layer-   41 lacquered surface that does not transmit light-   50 cover-   60 termination element

The invention claimed is:
 1. A radome having a substantially extensivefront plate, which is configured to be transmissive on a front side andwhich is provided on a rear side with a layer that does not transmitlight, wherein a cutout in the form of a light passage is formed in thelayer that does not transmit light, having a substantially extensivelight guide which is arranged on the rear side at the layer that doesnot transmit light, and having a light-emitting element which is coupledto the light guide such that light enters the light guide and such thatthe light propagates through the at least one light guide and enters thefront plate at the light passage such that it exits the front plate onthe front side.
 2. The radome as claimed in claim 1, wherein a diffuserelement is arranged at the light guide, which diffuser element isarranged such that the light propagating through the light guide entersthe diffuser element, propagates through the diffuser element, and exitsthe diffuser element and enters the front plate at a light passage suchthat it exits the front plate on the front side.
 3. The radome asclaimed in claim 1, wherein a plurality of light guides are provided,wherein assigned to each light guide of the plurality of light guides isa light-emitting element, which is coupled to the light guide forfeeding light into the light guide.
 4. The radome as claimed in claim 3,wherein a diffuser element is assigned to at least one of the pluralityof light guides.
 5. The radome as claimed in claim 4, wherein thediffuser element is arranged at an outer periphery of the light.
 6. Theradome as claimed in claim 4, wherein the diffuser element engagesaround a perimetric outer periphery of the light guide.
 7. The radome asclaimed in claim 1, wherein the light guide is made of a transparentplastics material and the diffuser element is made of a translucentplastics material.
 8. The radome as claimed in claim 1, wherein thelight guide and the diffuser element are placed to be next to oneanother in the form of separately configured parts.
 9. The radome asclaimed in claim 1, wherein the light guide and the diffuser element arearranged as interconnected parts in neighboring fashion.
 10. The radomeas claimed in claim 1, wherein a rear-side cover is provided whichcovers the light guide.
 11. The radome as claimed in claim 3, whereinassigned to each light guide is more than one light-emitting element.12. The radome as claimed in claim 4, wherein a diffuser element isassigned to each of the light guides.
 13. The radome as claimed in claim5, wherein the diffuser element rests against the outer periphery of thelight guide.
 14. The radome as claimed in claim 9, wherein the lightguide and the diffuser element are interconnected by way of injectionmolding or adhesive bonding.
 15. The radome as claimed in claim 2,wherein a rear-side cover is provided which covers the light guide andthe diffuser element.